1. Field of the Invention
The present invention relates to safety needle devices for safe and convenient handling of needles. More particularly, the present invention relates to a shieldable needle device having a forward moving safety shield for protection from a used needle tip.
2. Description of Related Art
Disposable medical devices having medical needles are used for administering medication or withdrawing fluid from the body of a patient. Such disposable medical devices typically include blood-collecting needles, fluid handling needles and assemblies thereof. Current medical practice requires that fluid containers and needle assemblies used in such devices be inexpensive and readily disposable. Consequently, existing blood collection devices typically employ some form of durable, reusable holder on which detachable and disposable medical needles and fluid collection tubes may be mounted. A blood collection device of this nature may be assembled prior to use and then disassembled after use. Thus, these blood collection devices allow repeated use of a relatively expensive holder upon replacement of relatively inexpensive medical needles and/or fluid collection tubes. In addition to reducing the cost of collecting blood specimens, these blood collection devices help minimize the production of hazardous waste material.
A blood collection device or intravenous (IV) infusion device typically includes a needle cannula having a proximal end, a pointed distal end, and a lumen extending therebetween. The proximal end of the needle cannula is securely mounted in a plastic hub defining a central passage that communicates with the lumen extending through the needle cannula. A thin, flexible thermoplastic tube is connected to the hub and communicates with the lumen of the needle cannula. The end of the plastic tube remote from the needle cannula may include a fixture for connecting the needle cannula to a blood collection tube or other receptacle. The specific construction of the fixture will depend upon the characteristics of the receptacle to which the fixture is to be connected.
In order to reduce the risk of incurring an accidental needle-stick wound, protection of used needle cannulas becomes important. With concern about infection and transmission of diseases, methods and devices to enclose or cover the used needle cannula have become very important and in great demand in the medical field. For example, needle assemblies commonly employ a safety shield that can be moved into shielding engagement with a used needle cannula to minimize risk of an accidental needle stick.
For example, U.S. Pat. No. 5,167,635 to Haber et al. discloses a safety IV catheter assembly including a catheter cannula which is retractable within a safety housing by rearward movement of a position control button through a slide track in the housing. The catheter cannula can be retained within the housing by positioning the control button within a locking detent at the rearward portion of the slide track. U.S. Pat. No. 5,501,672 to Firth et al. discloses hypodermic syringes and catheter devices in which a needle can be retracted within a wingset body. The body includes an open channel with pockets of varying widths, and the needle is connected to a slide member which slides within the channel. To retract the needle within the body, the slide member is depressed within the body, and tubing is pulled to retract the needle. U.S. Pat. No. 5,746,215 to Manjarrez discloses an IV device with an extendable and retractable needle. The needle can be extended against the force of a tension spring to lock in an extended state for use, and can be retracted by the tension spring to retract the needle within the housing. The device further includes a button which rides within a channel of the housing.
Such prior art devices are typically difficult to manufacture, require complex operation to operate, and do not provide for a needle clip for preventing re-emergence of the needle. In view of the foregoing, a need exists for a blood collection set including a shieldable needle device that achieves secure and effective shielding of a used needle cannula, which is easy to manufacture and is simple and safe to operate.